Improvement in electro-magnetic burglar-alarms



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WILLIAM B. GUERNSEY, 0F JERSEY CITY, NEW JERSEY.

Letters Patent No. 112,705, dated March 14, 18.71.

IMPROVEMENT IN ELECTRO-MAGNETIC BURGLARALARMS.

The Schedule referred to in these Letters Patent and making part of the same.

I, Wimmer B. GUnnNsnnof Jersey City,in thecounty of Hudson and State of New Jersey, have invented a new and useful Improvement in Electro-magnetic Alarms, of which the-following is a specification.

Nature all Objects of the Intention.

My invention. consists in an improved mode of arranging the conductors of my combined circuit-alarm, patented October 11, 1870, for the purpose of protection, such arrangement being particularly applicable to the protection otl safes, vaults, &c. also for windows, sky-lights, and other openings needing protection, but

in which it is desirable not to obstruct the passage of light or air.

4v'operatethe striking or sounding apparatus; or, if an electro-muguet be used instead ofthe galvanornetcr,

the obstruct-ing power of the resistance-coil or coils will boar such relation to that oi' the local circuit-closing magnet and of the bell-magnet that, untilA the main circuit is either broken or short circuited to avoid the resistance, the local circuit will remain open and the alarm inactive. The electrical current in its course also passes through wires so arranged that a portion of said conductor, between thepositive polel of thev battery and the resistance, shall; be nearly in contact with a portion between the negative pole and the resistance, yet separated'suoiently to prevent inagnctic communication between them, unless brought into contact by forcible means. ,i l

These wires or parts of a conductor are, preferably,

disposed, two or more together, ln cable form, hy'the use of some insulating materiahl and are arranged in a grated or similar shape, crossing each other in front of or within the opening to helprotected, so that, in the course of any surreptitious attempt to open the same, the wires will either be severed or brought in contact, in the former case breaking the circuit and causing the galvanometer to be delicctcd to its zero point, and in the latter short-eircuiting the current by causing it to pass directly from one set of wires to the other without passing through the resistance-coil, thusvdeflecting the galvanoineteizto the other extreme .of its arc, and, in either case, causing it to close a local circuit through the alarm; or, inthe case ot` shortcircnitng, as stated, the main circuit may suiiiceto sound the alarm withoutthe use of a local.

Description of the Accompanying Drawing. v lFigurc'l represents a coil or grating formed of a plurality of wires, insulated from each other, and connected with a battery, agalvanometer, an alarm, and

a resistance-coil.

Figure 2Y shows a modification inthe combination and arrangement ofthe wires.

Figure 3 is an elevation, partly in section, of a safe, with a resistance-coil and an;I automatic key or circuitcloser in connection with the battery and galvanometerI before referred to.

Figure 4 is a horizontal section of a portion of vthe safe, showing the door open and the short circuit closed. Figure 5 is a view of same parts, showing the door shut and the short circuit broken or open.

General Description.

A In'ay'represent an alarm of any suitable form, andI B, a battery connected therewith by wires XV and W', one of which passes through and controls a galvanometer, G.

. The wires W and W' are connected through a resistance-coil, It, causing such an obstruction ot' the electrical current that the galranometer-ueedle will be deliected-into 'a position intermediate between its two extremev points, as represented in the drawing, inthe-illustration here given vthe wires are shown` covered with an envelope of gotta-percheJ or other mt'terial which will serve to insulate them from each otlierwhile combining the two in one cable. This caiz ble, being arrangediu a number of coils or folds, preferable arranged crosswise and secured by any adequate means, will serve lasla barrier to preventaccess to any place whiclrisfto-be protected. The spaces in the grating thnsf'ormed ymay'vary in diameter from onel ortwoinches'to vsix inches, or more,according to the:

place .andl 'purpose forv whichfit is used.

For protecting th'eopenings of doors, windows, skylights, Spc., the spaces maybe vcomparatively large;" but, where `itis .used as a protecting envelope or casing for the doors or 4walls of safes, vaults, 85o., the spaces should be small'enough to prevent the effective introduction ot any instrument without detection.

lt' preferred, the insulatingenvelope may be dis! penseelv with, the coilsin one direction being formed of the wire W, and those in the 'other direction of the wire W', crossing the iirst, buft without cont-act. This' modification is illustrated in tig. 2.

For safe'brvault-doors orlwalls the wires will be arranged under thesurface in isuch a manner that any ,attempt to break through thi-.i door or wall will either vsever the conductor, th us dema gnetizin g th e galvanom eter, causing its needle to he deflected to zero, which,

by vmeans of mechanism noti necessary tir-describe,

closes a short circuit to soundan alarm, or willdiring the two wires or two parts W W. of the wire into j electrical contact, so as to avoid the resistance 1t,

thereby causing a stronger current through the main I circuit, which will deiect the needle in the other direcopened.

'lhis automatic key or circuit-closer may be constructed in a great variety of ways.

As au illustration, l have shown a pin, I?, which, when the door D is shut, will be ,held in, but when the door is open will be forced out by a spring, S, bringing the head p of the pin against buttons connected with the respective wires Tand W', so as to iorm a direct connection between said wires, avoiding the resistance It, with theeilect already explained.

While I have represented and rel'erred to a galvanometer for the purpose ct' illustrationpl do not coufine myself to the use of such an instrument, but propose to employ, in carrying out my invention, an electromagnet, or any forin of electro-motor which may be adapted for the purposes in view. `I have not thought it necessary to describe specifically any such instrument or the galvanmneter itself, because the coustruction of these instruments and the modes of substituting one for. another will be suiiiciently well nnderstood by those skilled in the art to which the invention agpertains.

The particular arrangement ot' devices by means of which the galvanomcter or other instrument sounds the alarm may be varied to suit the circumstances of the case, it being competent for anyintelligent person suiiciently conversant with the art to construct my apparatus to adapt this part of it to the particular use and locality for which it is designed, and the strength or loudiicss of the alarm to be sounded.

rlhe English patent ot' T. B. Maxon, numbered 717, of 1866, describes an alarm, in which the conductingwire is formed as acage `to protect a sal'e or other object, so that an alarm will be caused in the event ot said comlueting-wirc being severed. lhe objection to this device is, that it may readily be rendered inoperative by establishing a short circuit, avoiding the point at which it may be desired to cnt the wire. This objection is obviated in my invention.

Claims.

I claim as my invention-` 1. rlhe arrangement of my continuous conductor or conductors, patented October 11, 1870, to serve as a barrier for the protection ol safes, vaults, windows, Sac., substantially as herein set forth.

2. The combined coils f and l", arranged substantially as represented, so that they will be either severed or brought into contact by an attempt to pass through an opening', or to pierce a door, wall, or other object whichthey are employed to protect.

' lV. B. GUERNSEY.

Witnesses WM. l-I. Banamex, Jr., Ocravrcs KNIGHT. 

